Bottom Line:
A gradient exists between increasing BMI and direct healthcare costs and indirect costs due to reduced productivity and early premature mortality.Determining precise estimates for the increases is mired by the large presence of heterogeneity among the available cost estimation literature.Analyses of nationally representative cross-sectional datasets augmented by data from primary care are likely to provide the best data for international comparisons.

Background: The rising prevalence of overweight and obesity places a financial burden on health services and on the wider economy. Health service and societal costs of overweight and obesity are typically estimated by top-down approaches which derive population attributable fractions for a range of conditions associated with increased body fat or bottom-up methods based on analyses of cross-sectional or longitudinal datasets. The evidence base of cost of obesity studies is continually expanding, however, the scope of these studies varies widely and a lack of standardised methods limits comparisons nationally and internationally. The objective of this review is to contribute to this knowledge pool by examining direct costs and indirect (lost productivity) costs of both overweight and obesity to provide comparable estimates. This review was undertaken as part of the introductory work for the Irish cost of overweight and obesity study and examines inconsistencies in the methodologies of cost of overweight and obesity studies. Studies which evaluated the direct costs and indirect costs of both overweight and obesity were included.

Methods: A computerised search of English language studies addressing direct and indirect costs of overweight and obesity in adults between 2001 and 2011 was conducted. Reference lists of reports, articles and earlier reviews were scanned to identify additional studies.

Results: Five published articles were deemed eligible for inclusion. Despite the limited scope of this review there was considerable heterogeneity in methodological approaches and findings. In the four studies which presented separate estimates for direct and indirect costs of overweight and obesity, the indirect costs were higher, accounting for between 54% and 59% of the estimated total costs.

Conclusion: A gradient exists between increasing BMI and direct healthcare costs and indirect costs due to reduced productivity and early premature mortality. Determining precise estimates for the increases is mired by the large presence of heterogeneity among the available cost estimation literature. To improve the availability of quality evidence an international consensus on standardised methods for cost of obesity studies is warranted. Analyses of nationally representative cross-sectional datasets augmented by data from primary care are likely to provide the best data for international comparisons.

Mentions:
The breakdown of articles by scope was direct costs of obesity (6 studies), direct costs of overweight and obesity (22 studies), direct and indirect costs of obesity (7 studies), direct and indirect costs of overweight and obesity (7 studies) and indirect costs only (3 studies). Only those studies that addressed the direct and indirect costs of both overweight and obesity were included in this review. In total, 7 studies attempted to estimate the direct and indirect costs of overweight and obesity [32-38]. Of these, two did not measure indirect costs, looking instead at transfer payments [34], and out of pocket expenses [38]. These were excluded, leaving only 5 articles published since 2001 estimating the direct and indirect costs of overweight and obesity. This search strategy is outlined in Figure 1.

Mentions:
The breakdown of articles by scope was direct costs of obesity (6 studies), direct costs of overweight and obesity (22 studies), direct and indirect costs of obesity (7 studies), direct and indirect costs of overweight and obesity (7 studies) and indirect costs only (3 studies). Only those studies that addressed the direct and indirect costs of both overweight and obesity were included in this review. In total, 7 studies attempted to estimate the direct and indirect costs of overweight and obesity [32-38]. Of these, two did not measure indirect costs, looking instead at transfer payments [34], and out of pocket expenses [38]. These were excluded, leaving only 5 articles published since 2001 estimating the direct and indirect costs of overweight and obesity. This search strategy is outlined in Figure 1.

Bottom Line:
A gradient exists between increasing BMI and direct healthcare costs and indirect costs due to reduced productivity and early premature mortality.Determining precise estimates for the increases is mired by the large presence of heterogeneity among the available cost estimation literature.Analyses of nationally representative cross-sectional datasets augmented by data from primary care are likely to provide the best data for international comparisons.

Background: The rising prevalence of overweight and obesity places a financial burden on health services and on the wider economy. Health service and societal costs of overweight and obesity are typically estimated by top-down approaches which derive population attributable fractions for a range of conditions associated with increased body fat or bottom-up methods based on analyses of cross-sectional or longitudinal datasets. The evidence base of cost of obesity studies is continually expanding, however, the scope of these studies varies widely and a lack of standardised methods limits comparisons nationally and internationally. The objective of this review is to contribute to this knowledge pool by examining direct costs and indirect (lost productivity) costs of both overweight and obesity to provide comparable estimates. This review was undertaken as part of the introductory work for the Irish cost of overweight and obesity study and examines inconsistencies in the methodologies of cost of overweight and obesity studies. Studies which evaluated the direct costs and indirect costs of both overweight and obesity were included.

Methods: A computerised search of English language studies addressing direct and indirect costs of overweight and obesity in adults between 2001 and 2011 was conducted. Reference lists of reports, articles and earlier reviews were scanned to identify additional studies.

Results: Five published articles were deemed eligible for inclusion. Despite the limited scope of this review there was considerable heterogeneity in methodological approaches and findings. In the four studies which presented separate estimates for direct and indirect costs of overweight and obesity, the indirect costs were higher, accounting for between 54% and 59% of the estimated total costs.

Conclusion: A gradient exists between increasing BMI and direct healthcare costs and indirect costs due to reduced productivity and early premature mortality. Determining precise estimates for the increases is mired by the large presence of heterogeneity among the available cost estimation literature. To improve the availability of quality evidence an international consensus on standardised methods for cost of obesity studies is warranted. Analyses of nationally representative cross-sectional datasets augmented by data from primary care are likely to provide the best data for international comparisons.